A New Isolated Railway Power Supply System Based on MMC and Scott Transformers

In view of the problems of negative sequence and neutral section existing in the current high-speed railway, a port-isolated co-phase power supply system based on modular multilevel converter (MMC) and Scott transformers is proposed. The structure of the proposed co-phase power supply system is designed, and its compensation principle and control system are analyzed. Compared with the existing co-phase power supply systems based on MMC, the proposed system can ensure the three-port isolation of power grid system, railway traction system and compensation system, and the active power compensator (APC) has a smaller capacity. Finally, correctness and validity of the proposed system is verified by simulation in MATLAB/Simulink.